Features

2.5 GHz bandwidth

4.0 k Hz typical input reference noise

2 MA maximum input current

123] Formation CML data output

Single power supply+3.3V power supply

naked mold options

[

[[

[[

[[

123] SONET OC-48

SDH STM-16

APD front placeder receiver

Put the front placed instrument receiver

Instructions

OneT2511TA

is a high -speed transmissions large device for SDH/SONET system with a data rate of up to 2.5Gbps. It has low input reference noise, 2.5GHz bandwidth, 4.0k cross -resistance and receiving signal strength indicator.

OneT2511TA device can be molded in the form of mold, and single power supply+3.3V is required. It is very power -saving and consumes less than 83 MW (typical). It is characterized by working at the temperature of -40 ° C to 85 ° C.

Available options

Detailed description

block diagram The amplifier can be divided into signal paths, filters and offset elimination blocks.

The signal channel is composed of cross -blocking large, voltage amplifier, and output buffer.

Filter circuit provides filter VCC for the optoelectronic diode.

The offset correction circuit uses an internal low -pass filter to eliminate the input end DC electricity and provide a signal to monitor the receiving signal strength.

The simplified box diagram of OneT2511TA is shown in Figure 1.

Signaling pathway

The first level of the signal pathway is a transmissile block, which receives the optoelectronic diode current and converts it to a voltage signal. The second level is to provide additional gain voltage amplifiers. The second -level output supply output buffer and offset elimination circuit. The third and last signal channel level of OneT2511TA is the output buffer. Output buffer is CML output mentionFor the chip, 50 back terminal to VCC.

Filter circuit

Filter foot provides filtering VCC for the bias of the optoelectronics diode. The low -pass filter on the optical diode VCC is achieved with a 750Ω filter resistance and internal capacitors. If the application requires additional filtering, the external capacitor should be connected to the filter pin.

Cancel off with RSSI

Displacement of the output signal of the voltage amplifier for low -pass filtering. This will induced the DC offset of the ONE2511TA input terminal. The circuit minus the current from the input terminal and effectively offsets DC power. The responding current is mirror and the RSSI output is generated through 10 K the resistor is generated. To disable the offset correction circuit, the filter pins should be connected to the GND.

The pad instructions

OneT2511TA provides naked molds. The position of the pad is shown in Figure 2. The circuit is characterized by the ambient temperature between -40 ° C and 85 ° C. Table 1 shows the PAD description of OneT2511TA.

Application information

Basic application circuit

FIG. 3 shows that one2511ta is used as a receiver in typical optical fiber applications. OneT2511TA converts the current generated by the PIN or APD optoelectronics diode to a differential voltage output. The filter input provides a DC bias voltage to the photoelectric diode. The voltage is filtered by a low -pass filtering by the internal 750Ω resistor and internal capacitors. For additional power filtering, an external capacitor C filter is used. The RSSI output is used for the output current of the image photovoltaic diode, which must be connected to GND or keep the road through 10-k the resistor must be connected to GND. In one2511ta, OUT+and OUT-pins are connected to 50

Circuit plate layout

Careful attention to pay attention to the lane layout parasitic and external components, to achieve the most high -performance crossover, such as ONE2511Ta the most Good performance.

The recommendations for optimized performance include:

1. By using low-capacitance photoelectric diode, and pay attention to the bandal capacitors, to minimize the total capacitance on In-PAD. Put the photoresistic diode in a place near the One2511TA chip to minimize the length of the connection cable, thereby reducing the parasitic inductance.

2. The external filter capacitor filter may affect the transmission function of the TIA, so you must choose carefully according to the module.

3. Use the same terminal and symmetrical transmission line at the differential output pins out+and out-.

4. Use a short -connected ground wire connection for the power terminal VCC and GND.Provide enough power supply voltage filtering.

chip size and pad position

TO46 layout example

An example of a 5 -pin TO46ROSA is recommended.

Typical features

VCC +3.3 v and TA +25 ° C (unless there are other instructions).